In this model there are five platonics nested: a tetrahedron (yellow) inside of an octahedron (green), inside of a cube (light blue), which is surrounded by an icosahedron (dark blue), inside of a dodecahedron (black). The vertices of the "inner" shapes are situated 1 cm above the centers of the faces of the "outer" ones. I first saw an arrangement like that in a VRML-file of Alex Doskey.